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Bendia AG, Callefo F, Araújo MN, Sanchez E, Teixeira VC, Vasconcelos A, Battilani G, Pellizari VH, Rodrigues F, Galante D. Metagenome-Assembled Genomes from Monte Cristo Cave (Diamantina, Brazil) Reveal Prokaryotic Lineages As Functional Models for Life on Mars. ASTROBIOLOGY 2022; 22:293-312. [PMID: 34694925 DOI: 10.1089/ast.2021.0016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Microbial communities have been explored in various terrestrial subsurface ecosystems, showing metabolic potentials that could generate noteworthy morphological and molecular biosignatures. Recent advancements in bioinformatic tools have allowed for descriptions of novel and yet-to-be cultivated microbial lineages in different ecosystems due to the genome reconstruction approach from metagenomic data. Using shotgun metagenomic data, we obtained metagenome-assembled genomes related to cultivated and yet-to-be cultivated prokaryotic lineages from a silica and iron-rich cave (Monte Cristo) in Minas Gerais State, Brazil. The Monte Cristo Cave has been shown to possess a high diversity of genes involved with different biogeochemical cycles, including reductive and oxidative pathways related to carbon, sulfur, nitrogen, and iron. Three genomes were selected for pangenomic analysis, assigned as Truepera sp., Ca. Methylomirabilis sp., and Ca. Koribacter sp. based on their lifestyles (radiation resistance, anaerobic methane oxidation, and potential iron oxidation). These bacteria exhibit genes involved with multiple DNA repair strategies, starvation, and stress response. Because these groups have few reference genomes deposited in databases, our study adds important genomic information about these lineages. The combination of techniques applied in this study allowed us to unveil the potential relationships between microbial genomes and their ecological processes with the cave mineralogy and highlight the lineages involved with anaerobic methane oxidation, iron oxidation, and radiation resistance as functional models for the search for extant life-forms outside our planet in silica- and iron-rich environments and potentially on Mars.
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Affiliation(s)
- Amanda G Bendia
- Biological Oceanography Department, Oceanographic Institute, Universidade de São Paulo, São Paulo, Brazil
| | - Flavia Callefo
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Maicon N Araújo
- Fundamental Chemistry Department, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil
| | - Evelyn Sanchez
- Institute of Science and Technology, Federal University of the Jequitinhonha and Mucuri, Diamantina, Brazil
| | - Verônica C Teixeira
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Alessandra Vasconcelos
- Institute of Science and Technology, Federal University of the Jequitinhonha and Mucuri, Diamantina, Brazil
| | - Gislaine Battilani
- Institute of Science and Technology, Federal University of the Jequitinhonha and Mucuri, Diamantina, Brazil
| | - Vivian H Pellizari
- Biological Oceanography Department, Oceanographic Institute, Universidade de São Paulo, São Paulo, Brazil
| | - Fabio Rodrigues
- Fundamental Chemistry Department, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil
| | - Douglas Galante
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
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Calabrese EJ. The linear No-Threshold (LNT) dose response model: A comprehensive assessment of its historical and scientific foundations. Chem Biol Interact 2019; 301:6-25. [PMID: 30763547 DOI: 10.1016/j.cbi.2018.11.020] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/26/2018] [Indexed: 11/24/2022]
Abstract
The linear no-threshold (LNT) single-hit (SH) dose response model for cancer risk assessment is comprehensively assessed with respect to its historical foundations. This paper also examines how mistakes, ideological biases, and scientific misconduct by key scientists affected the acceptance, validity, and applications of the LNT model for cancer risk assessment. In addition, the analysis demonstrates that the LNT single-hit model was inappropriately adopted for governmental risk assessment, regulatory policy, practices, and for risk communication.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
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